The patient, who has not been publicly identified, remains quarantined in New York's Bellevue Hospital, according to the health department.

Authorities had said Thursday that tests were being conducted to determine if the patient has Ebola. Though the patient remains quarantined, another set of tests will be conducted in the coming days to confirm the negative diagnosis.

On Wednesday, authorities said Ebola tests done on a woman who died Tuesday in New York after arriving from Guinea Conakry had also turned out negative.

The woman had arrived in New York 19 days ago from the West African nation, one of those that has been most severely affected by the Ebola epidemic, and she apparently died of a heart attack.

The only Ebola case diagnosed so far in New York was that of Craig Spencer, who had been working in Guinea from mid-September to mid-October.

After experiencing symptoms and testing positive for Ebola, Spencer was pronounced fully cured and released Nov 11 from the hospital where he had been quarantined and treated.

Prior to that, other cases where people showed Ebola-like symptoms in New York City tested negative for the deadly virus. Around 300 people deemed to be at risk are currently being monitored in New York.